Cellulose composition and process



. Patented May 6, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM G. LINDSAY, O'F NEWARK, NEW JERSEY, ASSIGNOR TO THE CELLUIDII) C OIMZIEANY, A CORPORATION OF NEW JERSEY.

CELLULOSE COMPOSITION AND PROCESS.

No Drawing.

To all whom it may concern:

Be it known that I, WILLIAM G. LINDSAY, citizen of the United States, residing at Newark, in the county of, Essex and State of New Jersey, have invented certain new and useful Improvements in Cellulose Compositions and Processes, of which the following is a specification. I

This invention relates to a process for rendering certain inflammable materials, substance, or compounds, non-inflammable, and to the preparation of commercially useful non-inflammable articles, such as paper,

textile fabrics, cellulose plastics, pyroxlyn.

a heat absorbing compound capable of ab sorbing or taking up through decomposition, volatilization, or other change, all or the major part of the heat that would be necessary to raise the material or its components to the point at which ignition could be sustained.

This heat absorbing, or endothermic substance or compound should be of such nature that it will decompose, or otherwise be in condition to absorb heat, before or when the temperature of combustion of the material to be rendered non-inflammable has been reached. The absorption of heat will thus proceed at such a rate as to prevent the combustible material from attaining its temperature of ignition.-

Application filed A ril 25, 1922. serial No. 556,531.

pacity,on decomposition in that it may be desired to impart other properties to the resultant product. The relative proportions of the combustible substance, i. e., the sub stance to be rendered non-inflammable, and endothermic or heat absorbing substance, will be varied somewhat to' meet conditions of strength, plasticity, trans arency, or other desirable characteristics, ut in general will be dependent upon the amount of decomposition, in heat unit equivalents, that can take place at or below the temperature at which combustion could be sustained by the exothermic compound if the heat of como bustion were not absorbed at a greater rate than that at which it could be liberated. The general rule is that a suflicient quantity of endothermic substance should.be employed to absorb u onits decomposition, a sufficient amount 0? tained combustion of the said exothermic: substance.

In carrying out my invention, any one of I a number of products may be the aim. The characteristics of these products may vary from that of a hard, non moldable, dense solid sheet material which may beused for cutting out various objects such as brush backs, mirror backs, knife handles, etc., to

that of a thin, highly flexible product which may be used forthe veneering of fabrics, paper and the like or which can be used in place of various textiles and other flexible materials. The flexible compound may also be used as a substitute for leather. It may also possess the necessary characteristics required in com ounds that are to be molded such as molde boxes, molded handles, molded brushes, mirrors, etc.

' In carrying out the invention the procedure will vary according to the nature and 9d physical properties of the material treated. The exothermic substance which I pro ose to use will be nitrocellulose, acetylcellu ose, or some cellulosic ester, ether, derivative, or compound. n

In the followingexamples I give such proportions as will be applicable to oompounds containing nitrocellulose, as this is heat to prevent a sus'. I

. facture, should be of such nature that the p ate is incorporated, the method for which point of ignition is relatively hi h. In my experiments I have found that t e organic phosphates ossess the necessary characteristics of solu ility-and at the same t me possess the requisite temperature of ignition. The most satisfactory results are produced 'with the aromatic phos hates because of their relatively high stability and resistance to decomposition, and because they possess at the same time the necessary solvent or plasticizing efiect on the nitrocellulose, as well as a relatively high ignition point.

To a mixture of nitrocellulose and an aromatic phoshate, as for example, liquid tricresylphosphate, I add a suficient amount of calcium tartrate to prevent the combined mixture from sustaining ignition upon the application and withdrawal of a flame. An example of. proportions for this purpose is 100 parts of pyroxylin, 7 5 parts of li uid tricresylphos hate, and 125 parts of cafiicum tartrate aCJ-LO PQO.) Material of this composition, when manufactured according to the usual methods as obtain in the py' roxylin plastic industry, will possess hardness, toughness and moldability in similar de ree to the usual varieties of celluloid, manufactured in the form of ivory, opaque colors and the like.

In the manufacture of these non-inflammably compounds ll proceed substantially as in the manufacture of ordinary pyroxylin plastic materials incorporating the calcium tartrate compound with the soaked or colloidized mass of pyroxylin and liquid tricresylphosphate prior to final mastication on the rolls. This incorporation may be effected in kneaders or the calicum tartrate compound may be directly added during the course of mastication on the rolls. The calcium tartrate compound may also be. incorporated with the pyroxylin in the same 0 eration in which the liquid tricresylphosis described in my" U. S. Patent No.

1,233,374, granted July 17, 1917. In accord-' ance with this method the wet pyroxylin is mixed with the non-volatile solvent such as tricresylphosphate and the mixture subjected to the'water.

pressure and absorption to remove naeaaoe In the choice of liquid volatile solvent I may select any one or a combination 0 a number of the common ordinary solvents, such as methyl alcohol, ethyl alcohol, acetic ether, acetone, amyl acetate, or the various commerical grades and m1xtures of these M compounds as are ordinarily found upon the market. a In the manufacture of the flexible non inflammable compound having the proper- 7 ties of leather and the like, ll proceed as in the example specified but instead of employs,

ing parts of liquid tricresylphosphate, I increase the amount to 200 parts to 100 parts pyroxylin. Material of this composition 90 may be worked up according to the usual method for the manufacture of pyroxylin plastic compounds and produced in the form of sheets by shaving from a block, or it may be dissolved in a suitable proportion of solvent such as wood alcohol, acetone and the like and spread upon a suitable surface supth 1as textile fabric, leather and the like.

1. A composition containing a cellulose taining calcium tartrate,-said latter ingredient being present in excess of 25% oi said composition.

5. A. composition containing pyroxylin, an aromatic phosphate and a fire retarding ingredient compnsing calcium tartrate.

6. A composition containing pyroxylin, tricresylphosphate and a fire retarding ingredient comprising calcium tartrate.

- 7. The process which consists in mixing tricresylphosphate and calicumtartrate with hydrous pyroxylin and subjecting the mixture to pressure to remove water'therefrom.

8. The process which-consists m mixing liquid trioresylphosphate and calcium tartrate with hydrous pyroxylin, removing the water therefrom by pressure and absorption and manipulating the mixture in the presence of a volatile solvent.

9. A composition having substantially the toughness and 'moldabihty of the usual pyroxylin plastics and containing in excess of 30 or cent calcium tartrate.

10. tough consolidated non-i r1; :7. .m; a bl cellulose composition containing calcium tartrate.

11'. A tough non-inflammable cellulose composition containingicaloium tartrate in 5 excess of 25 per cent of said composition.

12. A- composition having, s11

ti'ate' insuffic ient stantially the physical properties of the usual pyroxylin plastics. and containing as a fire "retarding material calcium tartrate. v v

13.; A composition comprising a non-. fibrousjcellulosic material and calcium tarquantity to produce a fire retarding efl'ect. I

, W LLIAM LINDSAY. 

